Saw this in the MySQL docs. I'm assuming this only works for relational databases.
I don't know if it's very useful but definitely interesting.
MariaDB[] > SELECT SIN(PI()/4), (4+1)*5;
+------------------+---------+
| SIN(PI()/4) | (4+1)*5 |
+------------------+---------+
| 0.70710678118655 | 25 |
+------------------+---------+
1 row in set (0.02 sec)
postgres=# SELECT SIN(PI()/4), (4+1)*5;
sin | ?column?
--------------------+----------
0.7071067811865475 | 25
(1 row)